Re: Polyester Plates
The main problem with Poly Plates on GTOV or older machines generally comes back to the Clamps, nothing to do with packing, pressures or alignment of the planets.........
On auto plate load machines the front loading clamp is fixed hence when loaded automatically the tension and positioning of the plate is near identical every time, i.e.: QM & SM machines are excellent for Poly.
When plates are loaded automatically, very little adjustment is needed to get the plates registered due to the precision they are placed on the plate cylinder.
This is not the case for GTO clamps. When an existing set of plates are removed, the clamps move/flop around a couple of mm so when the next set of punched plates is put into the clamps ( even from the same DPX for example ) the plates have to be registered together again, by means of push, pulling and cocking the plate in the clamps. This is where the stretching occurs +and it is stretching+ , the clamps are not fixed and the operator tightens the back edge and cocks the plate on each clamp with a slightly different torque. ( We've tried torque spanners, locking the front edge of the clamps etc..)
So as mentioned previously, it comes down to the condition of the clamps, and the quality of your operator and how much finesse he/she can set 4-5-6 plates.
We have both the auto plate and the manual plate Heidelberg Machines.
The main problem with Poly Plates on GTOV or older machines generally comes back to the Clamps, nothing to do with packing, pressures or alignment of the planets.........
On auto plate load machines the front loading clamp is fixed hence when loaded automatically the tension and positioning of the plate is near identical every time, i.e.: QM & SM machines are excellent for Poly.
When plates are loaded automatically, very little adjustment is needed to get the plates registered due to the precision they are placed on the plate cylinder.
This is not the case for GTO clamps. When an existing set of plates are removed, the clamps move/flop around a couple of mm so when the next set of punched plates is put into the clamps ( even from the same DPX for example ) the plates have to be registered together again, by means of push, pulling and cocking the plate in the clamps. This is where the stretching occurs +and it is stretching+ , the clamps are not fixed and the operator tightens the back edge and cocks the plate on each clamp with a slightly different torque. ( We've tried torque spanners, locking the front edge of the clamps etc..)
So as mentioned previously, it comes down to the condition of the clamps, and the quality of your operator and how much finesse he/she can set 4-5-6 plates.
We have both the auto plate and the manual plate Heidelberg Machines.
